event/dlb2: update rolling mask used for dequeue
event/dlb2: update rolling mask used for dequeue

Update the rolling mask used in dequeue operations to
fix the vector optimized dequeue.

Fixes: 000a7b8e7582 ("event/dlb2: optimize dequeue operation")
Cc: stable@dpdk.org

Signed-off-by: Timothy McDaniel <190d0658596d144b7d6e7de3c5d6e0f14d01ed54@intel.com>

john-mcnamara-intel/dpdk,john-mcnamara-intel/dpdk,john-mcnamara-intel/dpdk,john-mcnamara-intel/dpdk